This disclosure relates to a developing device favorably loaded on an image forming apparatus such as a copier or a printer, and the image forming apparatus provided therewith.
An image forming apparatus is provided with a developing device. The developing device is composed of a developing housing provided with a developing roller and a stirring screw; and a toner container detachably fitted to this developing housing for toner refill. Provided at a bottom part of the toner container is an openable and closable toner discharge port, and provided at a position corresponding to the toner discharge port in the developing housing is a toner refill port.
After the toner container is fitted to the developing housing and the toner discharge port and the toner refill port are opened, a toner in the toner container is supplied to a predetermined circulatory conveyance path formed in the developing housing.
The circulatory conveyance path is composed of: an outward conveyance path corresponding to the toner refill port; and a return conveyance path corresponding to the developing roller. Each circulatory conveyance paths is fitted with a stirring screw having a screw blade disposed around a rotation axis. A toner is conveyed by these stirring screws between the outward conveyance path and the return conveyance path in a circulating manner.